Is there any way to resend login credentials to a collaborator?

This is a great point - at this point we have no link you can click to resend login credentials to a contributor. We don't have this mostly for security reasons: having such a link would mean storing everyone's passwords as plain text on our database, something we don't want to do in order to keep security as tight as possible. We could, however, have a "send a password reset email" link, although it would be less useful in the cases where the contributor knows his password and the company administrator thinks he doesn't. We'll definitely think about this issue.

Solving your problem is simpler, however. You can add a new contributor to the project and use your client's email. He'll get a new password to join the project on Goplan on his email account, and that should be it.

We hope to have you moving over to Goplan soon! Let me or the rest of our team know if you have any issues or need a hand. Cheers!